Note 3 - Loans and Allowance for Loan Losses - Activity for Troubled Debt Restructurings (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Beginning Balance	$ 6,414,000	$ 8,587,000
Charge-Offs	0	0
Payments	(2,676,000)	(2,832,000)
Transfers to ORE	0	0
Net Additions/Deletions	22,000	6,449,000
Ending Balance	3,760,000	12,204,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Beginning Balance	0	85,000
Charge-Offs	0	0
Payments	0	(3,000)
Transfers to ORE	0	0
Net Additions/Deletions	0	0
Ending Balance	0	82,000
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Beginning Balance	14,797,000	1,145,000
Charge-Offs	0	0
Payments	(910,000)	(988,000)
Transfers to ORE	0	0
Net Additions/Deletions	0	3,654,000
Ending Balance	13,887,000	3,811,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Beginning Balance	480,000	178,000
Charge-Offs	0	0
Payments	(9,000)	(4,000)
Transfers to ORE	0	0
Net Additions/Deletions	0	0
Ending Balance	471,000	174,000
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Beginning Balance	0	7,000
Charge-Offs	0	0
Payments	0	(4,000)
Transfers to ORE	0	0
Net Additions/Deletions	0	0
Ending Balance	0	3,000
Retail Portfolio Segment [Member] | Home Equity and Other [Member]
Beginning Balance	1,146,000	1,415,000
Charge-Offs	0	0
Payments	(118,000)	(29,000)
Transfers to ORE	0	0
Net Additions/Deletions	71,000	66,000
Ending Balance	1,099,000	1,452,000
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Beginning Balance	806,000	724,000
Charge-Offs	0	0
Payments	(22,000)	(9,000)
Transfers to ORE	0	0
Net Additions/Deletions	36,000	0
Ending Balance	$ 820,000	$ 715,000